1. Field of the Invention
This invention relates to a gas turbine generating system and more particularly to such a system using high pressure hydrogen and oxygen as the combustion fuel resulting in steam as the motive fluid of the gas turbines.
2. Description of the Prior Art
The current interest in alternative sources of energy production has lead to the investigation of the economical use of fuels other than the naturally occurring carbonaceous fuels. Recently, it has been suggested that wind-driven electric generating units be installed on the waters of the continental shelf. From such units, hydrogen could be produced electro-chemically and transferred to the mainland as a storable fuel for use in fuel-cell power generators. (See Proceedings of the 8th Annual Marine Technology Conference, September, 1972, pp. 435-466 "Power From the Off-Shore Winds," by W. E. Heronemus.)
Also, the generation of power from the combustion of hydrogen and oxygen cryogenic propellants has been suggested in that the electrolytic release of hydrogen from water also produces oxygen which can also be stored for subsequent combustion to generate power when needed. As proposed, the separately stored oxygen and hydrogen would be combusted together in the presence of a combustion flame coolant (water) to develop a motive fluid (steam) which is first passed through a heat exchanger and then to a turbine inlet. The motive fluid is exhausted from the turbine and reheated in the heat exchanger via the first passage therethrough and then delivered to the inlet of a second turbine. It is then exhausted into a condenser producing waste heat with a portion thereof being re-introduced into the combustor for again cooling the combustion process. (See Escher Technology Associates, "A Role for Liquid Rocket Advanced Technology in the Electric Power Crisis," prepared for Rocketdyne Division, North American Rockwell, January, 1971.)
It would be expected that for such a system as the latter to have a motive fluid inlet temperature of 2100.degree. F. or above (a typical gas turbine inlet temperature), the inlet temperature to the preceding heat exchanger would necessarily be at least as high as the initial inlet temperature to the first turbine plus the temperature rise required in the heat exchanger to raise the exhaust motive fluid from the first turbine to the inlet temperature of the second turbine. With the present turbine inlet temperatures being in the range of 2100.degree., it would be expected that the heat exchanger inlet temperature would be on the order to 3,000.degree. F. This temperature requirement places design restrictions on the heat exchanger that, in all likelihood, cannot be solved economically and yet provide the long-life expected of equipment in power generating systems.